The invention relates to a low pressure flap valve for an exhaust gas line of an internal combustion engine. Such low pressure flap valves are generally known from DE 10 2011 119 139 A1 and DE 10 2013 101 302 A1 and are used particularly for controlling the exhaust gas return in internal combustion engines in motor vehicles. The closure body of the valve is a flap which is fastened in a torque-proof manner on a shaft and is pivoted by an electromagnetic actuating drive connected directly to the shaft. By pivoting the flap, the mass flow of the returned gas can be controlled. Such flap valves have, with a relatively small overall size, a relatively large free cross-section and thereby enable a high mass throughput with a small pressure drop. They are therefore preferably used when exhaust gas is taken from the low pressure exhaust gas line. From the outlet opening of the valve, the exhaust gas can preferably be fed to the fresh air flow, which is fed to the internal combustion engine, for example upstream of a compressor.
An exhaust gas return is used in order to reduce the emissions of the internal combustion engine, in particular nitrogen oxides and other pollutants. The legal emission requirements for internal combustion engines, in particular for those in motor vehicles, have already increased greatly in recent years, especially in Europe and North America and will be further tightened considerably in the coming years.